16505213 has 2 divisors, whose sum is σ = 16505214. Its totient is φ = 16505212.

The previous prime is 16505179. The next prime is 16505261. The reversal of 16505213 is 31250561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13557124 + 2948089 = 3682^2 + 1717^2 .

It is an emirp because it is prime and its reverse (31250561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16505213 - 2⁶ = 16505149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16505273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8252606 + 8252607.

It is an arithmetic number, because the mean of its divisors is an integer number (8252607).

Almost surely, 2^16505213 is an apocalyptic number.

It is an amenable number.

16505213 is a deficient number, since it is larger than the sum of its proper divisors (1).

16505213 is an equidigital number, since it uses as much as digits as its factorization.

16505213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 16505213 is about 4062.6608275858. The cubic root of 16505213 is about 254.6089765053.

Adding to 16505213 its reverse (31250561), we get a palindrome (47755774).

The spelling of 16505213 in words is "sixteen million, five hundred five thousand, two hundred thirteen".